nvme_io(2)

💅 nvme_io — bestie's guide to submitting an NVMe user I/O command 💅

okay so. you want to send an actual I/O command to your NVMe device straight from userspace? iconic. this is the libnvme API manual page for nvme_io, and it's literally the door you knock on when you wanna yeet a command at the drive yourself. no cap. 🦋

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✨ NAME ✨

nvme_io — Submit an nvme user I/O command

like. that's it. that's the whole job. submit the command. slay. 👑

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🌸 SYNOPSIS 🌸

int nvme_io (struct nvme_io_args *args , __u8 opcode );

look at her. two arguments, one int return. main character energy fr fr. 🎀

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🦋 ARGUMENTS 🦋

• args — this is your struct nvme_io_args argument structure. it's the little bundle of everything you're telling the command: the details live in here, bestie, not in the function call itself. so pack it right. 🫶
• opcode — the opcode to execute. type is __u8, which is the fancy way of saying "one little byte." it's the actual command you're asking the device to run. this is the vibe check of your whole submission. ✨

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💀 RETURN 💀

okay so here's what you get back, and it's giving two very different moods:

• if a response was received, you get the nvme command status — and yes, that's the one from enum nvme_status_field, so go look at that enum if you wanna know what your status actually means. iykyk. 🔥
• otherwise, you get -1 and errno gets set. so check errno when things go sideways, because that's where the tea is. 😭

lowkey important: the -1 path only happens when there's no response at all. if you got a response, you're reading a status, not an errno. don't mix them up bestie. 💅

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🌈 that's the whole page 🌈

genuinely a short one, and honestly? we love a tight manpage. go forth and submit your I/O, you absolute legend. 🧚💖

anyway, this was nvme_io from the libnvme API manual, dated July 2026, living at section nvme_io(2) — so when you're deep in the docs at 3am, that's the address to find her at. periodt. 🎀⭐